【摘要】 本研究采用半自动熔化极气体保护焊打底(焊丝CHW50C6SM)+自动埋弧焊SAW填充和盖面对正火态60 mm厚DH36-Z35海工钢对接平焊，研究打底焊不清根对焊接接头微观组织和力学性能的影响。结果表明：焊接接头焊缝组织主要为先共析和针状铁素体，热影响粗晶区组织为板条和粒状贝氏体，细晶区为等轴铁素体和珠光体。打底焊不清根焊接接头的强度、塑性和-20℃冲击韧性与清根接头相当，满足焊接相关制造要求，可取消打底焊清根降低生产成本。更多还原

【Abstract】 Semi-automatic gas metal arc bottom welding(CHW50C6SM welding wire)+ automatic submerged arc fill and cover welding were used to butt flat welding of normalized marine engineering steel DH36-Z35 with 60 mm thickness. The microstructure and mechanical properties of welded joint without back chipping were investigated. The results showed that the weld zone of joint was mainly composed of proeutectoid ferrite and acicular ferrite. The coarse-grained heat affect zone was composed of lath bainite and granular bainite, and the fine-grained zone was composed of ferrite and pearlite. The strength, plasticity and impact toughness at-20℃ of the joint without back chipping were equivalent to the joint with back chipping, all of which met the requirements of relevant standards, and the bottom layer welding without back chipping technology can be canceled to reduce production costs.更多还原